Non-lethal projectiles are frequently required for dispersal of crowds during riots in order to restore order, and to prevent damage to property, or even injury and loss of life in severe circumstances. Rubber bullets are most frequently used for such crowd control purposes. A disadvantage of said rubber bullets is resulting injuries caused to the human target, which include amongst others, contusions, lacerations and loss of eyesight. Fatal wounds caused by rubber bullets have also been reported.
An alternative to rubber bullets is projectiles that deliver inhibitory or marking substances. These projectiles are launched using a gun having a barrel for directing the projectile, a propulsion system which generally consists of a compressed gas (generally carbon dioxide) cylinder that releases a measured flow of gas via a valve or similar gas release mechanism when the gun is fired, and a container for containing multiple projectiles, the container or hopper being capable of delivering a single projectile into the barrel for each subsequent shot fired by the gun. The projectiles are commonly manufactured from elastic materials such as plastic or gelatine, and generally comprise an elastic outer shell containing an inhibitory substance such as teargas or pepper spray in crowd control applications, or a marking substance in mock war games (commonly known as paintball sport) or similar applications.
These projectiles are designed to rupture upon impact with the intended target, thereby spreading the inhibitory substance among the crowd and causing the crowd to disperse, or marking the target with the marking substance, as the case may be. Whilst an impact with such a projectile is still relatively painful, the incidence of physical or debilitating injury caused by these projectiles is relatively insignificant when compared to rubber bullets.
Projectiles may also be used in operations where a substance is applied to and absorbed through the skin of the target, typically an animal. In this way, for example, a solution of chemicals for control of various pests and/or diseases associated with animals can be contained in the projectiles and be effectively applied to the animal without the requirement of capturing, containing and physically applying the chemical solution to the animal. Projectiles may further be used in animal immobilisation operations where immobilisation substances such as opioids, cyclohexamines or neuroleptics is injected intramuscularly into the animal by projecting a syringe or dart towards the animal, with the immobilisation substance being delivered intramuscularly when the syringe or dart pierces the skin of the animal.
Projectiles delivering any of the aforementioned substances usually comprise two hemispheres joined together after being filled with a marking, inhibitory or chemical substance, as the case may be. The disadvantage experienced with conventional spherical projectiles is that a spherical shape is inherently aerodynamically unstable in flight. Spinning round projectiles are affected by the Magnus effect, whereby any spin of the projectile induces pressure differences around the projectile, creating a force perpendicular to the direction of travel. The Magnus effect adversely affects the accuracy of the intended point of impact. An additional disadvantage is that a spherical shape travelling through air at a high enough velocity will create turbulent flow increasing drag dramatically. In addition, the inner volume of the spheres, and the volume of the substance deposited into the projectiles also differ. These differences in volume cause a fluctuating weight and centre of mass between subsequent projectiles, which further compounds the inaccuracy disadvantage. Inaccuracy problems experienced with bullets and arrows have historically been overcome by giving the projectile a spin around the axis parallel to the direction of travel during flight. However, with substantially round projectiles one cannot easily and reliably give the projectile a spin that will remain parallel to the direction of intended travel.
In an attempt to at least partially overcome the inaccuracy disadvantage, a plurality of stabilising fins has been added to projectiles. The intended purpose of these stabilising fins is to make the projectiles more aerodynamic, by evenly distributing the propulsion forces to the projectile, and causing the projectiles to follow a straighter and more consistently replicable flight path. Available finned projectiles have a substantially spherical front end, with a finned rear end or tail, the rear end or tail consisting of two or more fins having varying lengths. A disadvantage experienced with known finned projectiles is that the shape of the finned projectiles, and in particular the shape of the rear end of the projectiles often lead to ineffective loading and storage. A further disadvantage of the finned projectiles is that the shape of the finned projectiles does not allow the projectiles to be fed into the barrel of the gun in the same way that the spherical projectiles can be fed into the barrel of the gun from the container provided for the projectiles. This leads to a single projectile either having to be loaded into the barrel manually before each shot, significantly reducing the effectiveness of the weapon, or having to be placed in a magazine similar to pistol or rifle cartridges in a pistol or rifle magazine. However, this leads to a further disadvantage, in that, due to the finned tails of the projectiles, it is not possible for a plurality of projectiles to be stacked onto one another in a magazine, and to be fed into the barrel following each shot with replicable effectiveness.
An even further disadvantage of the finned projectiles is that the fins are easily damaged or bent during packaging, transport or handling, which may cause the projectile to veer off course when it is fired, or to jam in the barrel or magazine of the gun.
A yet further disadvantage of known projectiles, whether finned or not, is the volume capacity of the projectile. A relatively small amount of substance can be accommodated in the sphere of the projectile and there is a requirement, in particular in animal treatment operations, to provide a projectile with a larger volume so as to deliver a larger amount of substance to the target. Simply providing a projectile with a larger volume, i.e. larger sphere, will require the provision of a gun having a larger barrel, meaning that a separate gun need to be acquired for specific purposes.
A yet further disadvantage is that only a single substance, whether a marking, inhibiting or chemical substance can be delivered to the intended target by a single projectile. In many instances, it is preferable or even required to provide different substances, such as different chemical solutions, to be directed at the intended target. In known operations, this will require the firing of separate projectiles (in many instances by separate guns) to the intended target.
A yet further disadvantage of the known projectiles is that substantially no spin can be imparted along the longitudinal axis of the projectile, as there are no means on the projectile to transfer spin from rifling, if any, within the barrel of the gun to the projectile. This at least partially affects the accuracy of the projectile.